Progressively acting centrifugal regulators

ABSTRACT

The device is for insertion between a driven rotary member and a coaxial drive rotary member for progressively varying the angular position between them as a function of the speed of the drive member. The device is useful for regulating the injection lead angle for Diesel engines. The regulator is a self-contained assembly containing centrifugally-acting weights and torsion bars which are pre-set by screw stops enabling the limiting angular positions of the weights to be adjusted and consequently the minimal speed at which the regulator comes into play and the amplitude of the relative angular displacement between the driving and driven members.

United States Patent [191 Vuaille [451 Apr. 2 1 ,1973

PROGRESSIVELY ACTING CENTRIFUGAL REGULATORS Andre Vuaille, Lyon, France[75] Inventor:

Paris, France Filed: Feb. 16, 1971 Appl. No.: 115,431

[30] Foreign Application Priority Data [5 6] References Cited UNITEDSTATES PATENTS 1,590,772 6/1926 Moore ..64/25 3,552,146 1/1971Pischinger et a1. ..64/25 2,665,569 1/1954 Ens ..64/25 1,830,70411/1931- Chapelle ..64/25 2,929,371 3/1960 Rank l23/l39.13

Primary Examiner-Edward G. Favors Att0rneyWaters, Roditi, Schwartz &Nissen 5 7] ABSTRACT The device is for insertion between a driven rotarymember and a coaxial drive rotary member for progressively varying theangular position between them as a function of the speed of the drivemember. The device is useful for regulating the injection lead angle forDiesel engines. The regulator is a self-contained assembly containingcentrifugally-acting weights and torsion bars which are pre-set by screwstops enabling the limiting angular positions of the weights to beadjusted and consequently the minimal speed at which the regulator comesinto play and the amplitude of the relative angular displacement betweenthe driving and driven members.

6 Claims, 2 Drawing Figures PATENTEDAPR 24 I975 sum 1 Big 1PROGRESSIVELY ACTING CENTRIFUGAL REGULATORS more particularly, amongthese regulators, to those 7 which are for insertion in order to modifythe mutual angular relationship as a function of the speed, between thecrankshaft of a Diesel engine (to which the drive rotary member isconnected) and the cam-shaft of the injection pump supplying this engine(shaft connected to the driven rotary member).

It is an object of the invention to enable accurate adjustment of theminimal speed at which the regulator comes into play and of theamplitude of the maximal relative angular displacement between the twoabovesaid rotary members, i.e., in particular of the amplitude of thevariation of the injection timing.

The regulator according to the invention may comprise screw stop meansenabling the limiting angular positions of each of the weights to beadjusted. Preferably, these means are constituted by two screws borne byeach weight and adapted to limit the angular movement of the latterrespectively towards the axis of rotation of the regulator and away fromthis axis. Preferably again, the screw borne by one weight for limitingits angular movement towards the axis of rotation of the regulatorcooperates by abutment with the neighboring weight.

It is another object of the invention to render the regulator such thatthe return springs of the weights work with the minimum of friction.

To this end, the regulator according to the invention is characterizedby the fact that the return spring of each weight is constituted by atorsion bar aligned with the axis of rotation of this weight andanchored by one end to the latter and by the other end to the driverotary member.

It is yet another object of the invention, to facilitate the maintenanceof the regulator and to increase its life.

To this end, the regulator according to the invention is alsocharacterized by the fact that the drive rotary member forms part of acasing enclosing the driven rotary member which is constituted by acentral hub passing to the outside of this casing through rotary sealingjoints, the regulator thus forming a self-contained assembly and beingadapted to be greased during its assembling.

The invention will, in any case, be more fully un derstood with the aidof the supplementary description which follows as well as of theaccompanying drawings, which supplement and drawings relate to apreferred embodiment of the invention, given ofcourse purely by way ofillustrative but non-limiting example.

ln the drawings:

FIGS. 1 and 2 show, respectively from the front with portions removedand in axial section along the line 11-" of FIG. 1, an embodiment of acentrifugal regulator constructed according to the invention.

In order to construct a centrifugal regulator l for interpositionbetween the crankshaft of a Diesel engine (not shown) and the cam-shaft2 of the injection pump 3 supplying this engine, procedure is asfollows.

As regards the regulator, as a whole, it is constituted so that itcauses the angular position of a driven rotary member 4 to varyprogressively with respect to a coaxial drive rotary member 5, as afunction of the speed of rotation of the latter and that its weights 6,preferably two in number, are arranged to turn on the member 5 aroundaxes x-x and yy parallel to the axis of rotation XX of the regulator andare provided with individual return springs 7.

According to the invention, the regulator may comprise screw stop meansenabling adjustment of the limiting angular positions of each of theweights 6, these means being constituted, in the embodiment shown, bytwo screws 8 and 9 borne by each weight and adapted to limit the angularmovement of the latter, respectively towards the axis X-X and away fromthis axis. Each screw 8 and 9 is engaged in a threaded hole 10 or 11,which is formed in the weight 6, where it is retained by a lock-nut 12and bears a hexagonal round head 13 or the like, this head enablingadvancing or backing of the screw by means of a key and ensuring contactwith a stop surface. The screw 8 borne by each weight to limit itsangular movement towards the axis XX cooperates with a stop surface 14belonging to the neighboring weight, the geometric axis of this screw 8and the axis of rotation x--x or yy of the neighboring weights beingsubstantially concurrent and perpendicular between themselves.

The return spring 7 of each weight is constituted by a torsion baraligned with the axis of rotation xx or yy of this weight 6 and anchoredby one end to this weight and by the other end to the rotary member 5.The latter forms part ofa box which comprises, on one hand, a casingconstituting this member 5 and having a transverse base 5a and acylindrical part 5b and, on the other hand, a cover 15 held on the boxby screws 16.

The inner wall of the cylindrical part 5b constitutes the abovesaid stopsurface for the screws 9.

Each weight 6 comprises a hollow cylindrical portion 6a, traversed bythe torsion bar 7, and engaged inside bushes 17 and 18, the bush 17being borne by the base I 5a of the casing 5 and the opposite bush 18 bythe cover 15.

The hollow cylindrical portions 6a are axially open, which enables eachtorsion bar to be anchored by one end 7a (to the right in FIG. 2) to thebase 5a of the casing 5 which possesses for this purpose an anchoringhousing 19. The other end 7b of the bars 7 is anchored inside the hollowcylindrical portion 6a. On each side of the bars 7, flanges 20 and 21are fixed respectively to the base 5a of the casing 5 and to the cover15 by screws 22 and 23, toric seals 24 ensuring fluid-tightness betweeneach flange and the base 5a or the cover 15 and a flat seal 25 betweenthe cylindrical portion 5b of the casing 5 and the cover 15. The freeportion of each weight, i.e., that which is furthest from thecylindrical portion 6a and which bears the screw 8, is preferablyarranged in front of this cylindrical portion, in the direction ofrotation of the regulator shown diagrammatically by an arrow F (FIG. I).

The driven rotary member 4 is constituted by a hollow hub which ismounted in bushes 26 borne respectively by the base 5a and by the coverand which passes through the flanges and 21 inside rotary seals 27'.suchas lip seals. The hub 4 has lugs 4a which bear, two bytwo, axles 28 oneach of which can turn a block 29, of approximately square section,which slides in a groove 6b arranged on the inner face of each weight 6,so that the angular displacements of the weights around their respectiveaxes xx or y-y (in the bushes l7, l8) actuate relative angulardisplacements of the hub 4 with respect to the casing 5. I

The casing 5 is driven by the Diesel engine through a gear 30 which isfixed to the cylindrical portion 5b of the casing 5 by means enablingadjustment of its angular position with respect to this portion. Suchmeans can be constituted by screws which pass through arcuate slotsarranged on the gear 30 and are engaged in threaded holes 31 arranged ina collar 5c forming a projection at the periphery of the cylindricalportion 5b. As for the driven member or hub 4, it can be connected tothe cam-shaft 2 of the pump 3 fixed, on one hand, in rotation by a key32 and,.on the other hand, axially by a tubular nut 33 housed inside thehub 4, this nut 33 being screwed on the threaded end 2a of the shaft 2thereby thrusting against the hub 4. i

As a result of which, there is obtained a regulator of which theassembly and operation are as follows.

Firstly, in the workshop, the screws 8 are adjusted then the screws 9 onthe regulator l in order to set respectively the minimal speed at whichthe regulator comes into action (i.e., at which the screws 8 commence tobe separated from their respective stop surfaces 14) and the amplitudeof the maximal relative angular displacement of the hub 4 with respectto the easing 5, then the internal space of the regulator is greasedwhich is closed by flanges 20 and 21. This regulator then forms aself-contained assembly renderedl fluid tight by the seals 24, and 27.

The assembly thus formed is then keyed on the shaft 2 of the regulatorand the assembly of the regulator l and of the pump 3 is mounted on theengine by adjusting the angular displacement of the gear with respect tothe collar 50 of the casing 5.

' When it is in operation, the engine drives the casing 5 in rotation(in the direction of the arrow F, FIG, 1) by the gear 30 and the casing5 drives in its movement the weights 6 through the bushes 17. The rotarymovement is then transmitted to the cam-shaft 2 of the pump under theeffect of the centrifugal force and of the return torque exerted by thetorsion bars 7. Due to the fact that these bars are not subject to anyfriction in their operation, contrary to the case of conventionalsprings (especially spiral springs), they do not cause any hysteresis,i.e., the lead angle takes the same value at a given speed, whether thisspeed is reached during acceleration or during deceleration.

The desired correction can be obtained by varying the diameter of thetorsion bars 7, their pretorsion (by adjusting screws 8) and theamplitude of the correction (by adjusting screws 9). Frictional effectsare reduced to the minimum by the. selection which has been made of thereturn device for the weights (torsion bars) and, if necessary, by thenature of the bushes 17, 18 and 26 (self-lubricating metal resistant ofheavy loads).

As is self-evident and as already emerges from the precedingdescription, the invention is in no way limited to those of its methodsof application, nor to those of its methods of production of its variousparts, which have been more especially indicated; it encom passes, onthe contrary, all variations.

lclaim:

1. Centrifugal regulator adapted for progressively varying the angularposition of a driven rotary member with respect to a coaxial driverotary member as a function of the rotary speed of said drive member,said regulator comprising weights arranged to pivot on said drive memberaround axes parallel to the axis of rotation of the regulator, saidweights being provided with individual return springs, each said returnspring being constituted by a torsion bar anchored at one end to thecorresponding weight and at the other end to said rotary drive memberand passing axially through a hollow portion of said weight, said hollowportion of each weight being cylindrical, a casing forming part of therotary drive member and having transverse walls, two bushes borne bysaid transverse wallsrespectively of the casing, each'said weight beingengaged in two said bushes, the corresponding torsion bar being anchoredI atone endin an anchoring housing formed in one of through blocks 29,axles 28 and hub 4. The weights 6 v have a shape such that, for a lowspeed of rotation, the opposing torque of the pump, resisting the drivetorque, closes them by acting on the latter through the blocks 29. Thereis then, between the casing 5 and the hub 4, an angulardisplacementcorresponding to the injection lead angle which is suitablefor low speeds.

Above a certain rotary speed (determined, as a function of thecharacteristics of the torsion bars 7, by the pretorsion which isimparted to them by the screws 8), the weights, under the action ofcentrifugal force, separate from their initial position thereby drivingthe axles 28 and the shoes 29, which modifies the relative angularposition between the casing 5 and the hub 4 and, consequently, theinjection timing. The position of theweights 6 is, for each speed, anequilibrium position the transverse walls and at the other end insidesaid cylindrical hollow portion, said driven rotary member including ahollow hub possessing external connecting means for said weights andpassing outside the transverse walls of the casing through said bushes,and rotary seals sealing said hub at said walls.

2. Centrifugal regulator according to claim 1, wherein said screw stopmeans are constituted by two screws borne by each weight and adapted tolimit the angular movement of the latter, respectively towards the axisof rotation of the regulator and'away from said axis.

3. Centrifugal regulator according to claim 2, wherein the screw borneby one weight to limitits angular movement towards the axis of rotationof the regulator cooperates by abutment with the neighboring weight.

4. Centrifugal regulator according to claim 2, wherein the return springof each weight is constituted by a torsion bar aligned with the axis ofrotation of said weight and anchored by one end to the latter and by theother end to said drive rotary member.

5. Centrifugal regulator according to claim 3, wherein the return springof each weight is constituted by a torsion bar aligned with the axis ofrotation of said weight and anchored by one end to the latter and by theother end to said drive rotary member.

6. In a Diesel engine comprising a fuel injection pump, a cam-shaft ofsaid pump, and a crankshaft, a 5 regulator according to claim 1,interposed between said crankshaft and said cam-shaft to modify theirmutual angular relationship as a function of speed.

1. Centrifugal regulator adapted for progressively varying the angularposition of a driven rotary member with respect to a coaxial driverotary member as a function of the rotary speed of said drive member,said regulator comprising weights arranged to pivot on said drive memberaround axes parallel to the axis of rotation of the regulator, saidweights being provided with individual return springs, each said returnspring being constituted by a torsion bar anchored at one end to thecorresponding weight and at the other end to said rotary drive memberand passing axially through a hollow portion of said weight, said hollowportion of each weight being cylindrical, a casing forming part of therotary drive member and having transverse walls, two bushes borne bysaid transverse walls respectively of the casing, each said weight beingengaged in two said bushes, the corresponding torsion bar being anchoredat one end in an anchoring housing formed in one of the transverse wallsand at the other end inside said cylindrical hollow portion, said drivenrotary member including a hollow hub possessing external connectingmeans for said weights and passing outside the transverse walls of thecasing through said bushes, and rotary seals sealing said hub at saidwalls.
 2. Centrifugal regulator according to claim 1, wherein said screwstop means are constituted by two screws borne by each weight andadapted to limit the angular movement of the latter, respectivelytowards the axis of rotation of the regulator and away from said axis.3. Centrifugal regulator according to claim 2, wherein the screw borneby one weight to limit its angular movement towards the axis of rotationof the regulator cooperates by abutment with the neighboring weight. 4.Centrifugal regulator according to claim 2, wherein the return spring ofeach weight is constituted by a torsion bar aligned with the axis ofrotation of said weight and anchored by one end to the latter and by theother end to said drive rotary member.
 5. Centrifugal regulatoraccording to claim 3, wherein the return spring of each weight isconstituted by a torsion bar aligned with the axis of rotation of saidweight and anchored by one end to the latter and by the other end tosaid drive rotary member.
 6. In a Diesel engine comprising a fuelinjection pump, a cam-shaft of said pump, and a crankshaft, a regulatoraccording to claim 1, interposed between said crankshaft and saidcam-shaft to modify their mutual angular relationship as a function ofspeed.